The present invention relates to apparatus for handling safety valves used for shutting off high pressure upward flow through drill pipe or tubing.
When an oil well is being drilled, drilling personnel may encounter an unexpected high pressure situation requiring them to install a safety valve into the top of the drill pipe or tubing, from which uncontrolled high pressure fluids and gases are flowing.
Various methods are presently used to attempt such installation. The methods share a common feature of positioning the safety valve over the drill pipe while the valve is suspended by a cable, chain or rope catline. Typically, drilling personnel are required to physically align the end of the safety valve (which can weigh from 50 to 300 pounds) with the top of the drill pipe (which may be 5 to 8 feet off the working floor), while fluids and gases are escaping. If flowing pressures do not exceed 50 psi, the present methods can be successful. However, higher pressures can result in serious injury to personnel, either by movement of the suspended safety valve or impact from blown fragments of sand and gravel. If a safety valve cannot be installed, the only recourse is to allow the blowout to continue until the pressurized fluids are exhausted, or until the formation collapses, with detrimental environmental repercussions.
In U.S. Pat. No. 6,189,620, this inventor described apparatus for installing a safety valve. The present invention incorporates an improvement for stabilizing the hydraulic unit in extremely high pressure situations.
The present invention is directed to overcoming the problems associated with installing a suspended safety valve in extremely high pressure situations.
The present invention utilizes a three-stage double-acting hydraulic extension system to hold and stab a safety valve into the top of a drill pipe or tubing during extremely high pressure situation. The hydraulic extension system is mounted on a platform on wheels, which move on a track. Mounted on the platform next to the hydraulic extension system is a telescoping, mechanically-extending stanchion; a plate connects the top portion of the stanchion to the top of the hydraulic extension system. Attached to the hydraulic extension system is an extended arm with a clamp, which holds the safety valve. Also attached to the hydraulic extension system is a positioning arm, which is placed against the drill pipe or tubing in order to vertically align the safety valve. The length of both arms can be adjusted as necessary, by using the locking bolts. When not in use, the arms are out of the way. When the system is activated, the extended arm is rotated into position to align the safety valve directly over the drill pipe or tubing. The three-stage double-acting hydraulic extension system can raise the extension arm high enough vertically (up to 12 feet) to allow the operator to stabilize the safety valve, then lower it, without exposing drilling personnel to the well""s high pressures. The hydraulic unit can exert a downward force in excess of 3,000 psi through the extension arm, thereby preventing an oil well blowout the possibility of a fire, and environmental damage. The stanchion, which extends and retracts along with the hydraulic extensions, prevents any rotational movement of the hydraulic extensions. After lowering the valve into the drill pipe or tubing, the hydraulic extension system can hold the valve in position while a single crew member makes up the valve and closes the well in. Even these functions can be located and operated remotely, so that no drilling personnel need to be near the well during any part of the process. Because the present invention greatly reduces the length of time required to install a safety valve in unexpected high pressure situations, its use greatly improves safety for drilling personnel.
It is an object of the present invention to provide an apparatus to hold and stab a safety valve into a drill pipe or tubing when gases and liquids are flowing therefrom in an uncontrolled manner.
It is another object of the present invention to provide an apparatus which can be operated remotely, thereby keeping drill personnel away from hazardous conditions.
A further object of the present invention is to provide an apparatus which can operate properly and effectively, even in extreme high pressure situations.
It is still another object of the present invention to provide an apparatus which operates quickly and efficiently to bring a well under control.
Yet another object of the present invention is to shut down a burning oil well, extinguish the fire, and prevent damage to the environment.